Huawei inverter stopped with alarm 2102 Protection upon Communication Failure. How do I get it running?

The short answer

Fix the comms cable; the device recovers on the next scheduling command. The installer can disable the protection if not needed.

Plain explanation

From the Huawei manual for the SUN2000 + SmartGuard/scheduler: Check the communications cable is connected properly. After communication is restored the device recovers on the next scheduling command. The rest of the checklist is below; work through it in order. Installer only: DC and AC work on a live PV system is dangerous, so owners should note the code and call their installer.

Steps from the source

Check the communications cable is connected properly
After communication is restored the device recovers on the next scheduling command
If this protection is not needed, installer disables it

Source

Huawei Inverter Alarm Reference, Issue 09 (2024-11-01), EDOC1100345192, Alarm 2102, §64, p77files.keno-energy.com ↗

Where installers ask this

General guidance based on the manufacturer's manual or the named source. Always follow the current manual for your exact model and your national code. DC and AC electrical work is for qualified installers only. Not affiliated with or endorsed by any brand named; trademarks belong to their owners.